1. Technical Field
The invention relates to electric hair clippers, and more particularly to the means for releasably operably attaching cutting head assemblies to the clipper bodies of electric hair clippers.
2. Related Prior Art
It is generally known to provide an electric hair clipper with a cutting head assembly which can be releasably and operably mounted on the clipper. The provision of a releasable cutting head assembly facilitates the cleaning and replacement of the cutting head assembly. Typically, an electric hair clipper for use with a releasable cutting head assembly includes a body and a spring-loaded, pivotable support tongue which is fixed to one end of the clipper body. The support tongue is engageable with the associated cutting head assembly to hold the cutting head assembly in an operable position on the clipper body. When the tongue is pivoted forwardly to an "open" position away from the body, the cutting head assembly can be placed on the tongue. When the tongue is snapped into a "closed" position against the clipper body, the cutting head assembly is held securely against the clipper body.
Two examples of releasable cutting head assemblies for use in association with a hair clipper are illustrated in U.S. Pat. Nos. 2,182,597 and 2,928,171 which issued to a predecessor-in-interest of applicant on Dec. 5, 1939 and Mar. 15, 1960, respectively. The above-listed U.S. patents illustrate cutting head assemblies which include a tongue-receiving socket for mounting the assembly on an associated support tongue.
Under some circumstances, it is undesirable for cutting head assemblies to be interchangeable between various electric clippers. One such circumstance is where the blades of the cutting head assembly, given their relative size and other physical characteristics, such as the number of cutting teeth per blade, require a specific range of horizontal (i.e., side to side) movement or "sweep" of the motor-driven lever of the clipper in order to cut efficiently.
Previously, it was known in the art to provide a clipper with a support tongue having a specific configuration which could only releasably engage a particular cutting head assembly having a correspondingly configured tongue-receiving socket, but which could not releasably engage a cutting head assembly having a differently configured tongue-receiving socket. For example, one type of support tongue known in the prior art has a relatively uniform thickness across the width of the tongue and has a generally planar bottom surface. Another type of support tongue known in the prior art has a varying thickness across the width of the tongue and is characterized by two ribs which are disposed on the bottom surface of the tongue and which extend downwardly. A cutting head assembly configured for use in association with a clipper having the first type of support tongue, i.e., a tongue having a generally planar lower surface, cannot be used interchangeably with a clipper having a support tongue including a ribbed bottom surface because the downwardly extending ribs prevent engagement of the tongue with the tongue-receiving socket.
U.S. Pat. No. 5,092,048, which issued to Sukow, et al., on Mar. 3 1992 teaches means, however, for allowing the tongue-receiving socket to be releasably engaged with various support tongues having differing configurations, i.e., having either a planar or ribbed bottom surface. Thus, the device described in the '048 patent to Sukow, et al., can provide for the combination of a cutting head assembly and a clipper body that were not designed to be used together and which results in a clipper that does not cut with optimum efficiency.